SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bf7032ffa568f6fd7b787329e0d2d8b224d69e9ccc6299cdf7a1d61ce5d987c' 
  AND token = '7XiuojqbMiYwzJ2i4mhehkqlo23mAUIGjMxCnZkQAOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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