SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08bb1cb08b6d3af441bcc9bcdec82614a4755e78362472a8f5fddf356d06a4f9' 
  AND token = 'C0VAnGHX4ngz9LRAj7F/rCoq8j2+wre7fTDN1q2ypQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00068

JSON explain

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