SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a1506e3c58061fa6f2c05ed0853456a4eadfd840184ba488f4ab789eb4f4c55' 
  AND token = 'hCWjcKg0+jn1sQt15IaAdrd2hz1yqZ05ndEWYMuKfME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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