SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b3415d0206d217ea90fbafec784d025b83b83084246c52b4801222f601e70ef' 
  AND token = 'mqcD5YT2Ji6F3pftdrTNJf18kt4gSTmwaby76fvIqmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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