SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22e9306dd39ca71c33a9235513193db741331e9b138f15a60b0bad560427dfa6' 
  AND token = 'axTIs10vAvsW4ZNMth7lKY/9DBuPTsyRcH/Kcavj0MM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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