SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bb77ee4ea16f79b9f73dd0db25093b5a4ba212397777f494b656d329a5a78b4' 
  AND token = 'YESKp1c2cUqqTnSQnT4ZRnaxduopbqHEFH0/mHJeUck=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}