SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5631726ffc740321109386e623e988deaf902df16cceda18440fc5149d0fd468' 
  AND token = 'VywGu6pRolwz3yQWInVk46RYHLUV6psOIEQz43LWvSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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