SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f238739f4db204a3b95dfa321581e845309762fe842e6584c1aca9aaf5846e3e' 
  AND token = 'ji/qD4E5c8bvIZeTdAPoeiM4DVuS0Zn3HAemERKtqcM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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