SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6055eaeb283a8be5253a0c8e98c64270a84d54078b821ea749f7752cdb2bf45' 
  AND token = '1PMka2mrDbvGTo/9+skKZZg6U9kF+yJ6yLsqF+Y6/rA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}