SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d77c1851e82887a658882a93eeff1ad6379739fcf59aebf1959d07ba37ef74d' 
  AND token = 'G/1EFE8cM9/ljxw/rapypA9EoNTceL3NEkPRYbvMZLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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