SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc8545f9e0d0e38bd4e94b0b7fa45549b1253fe7936d95ec381136a30fbeec5c' 
  AND token = 'x0VS/i5GEVoc5hBfaKr7HBsX1fqrzSavBUYWNb9zXpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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