SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ee78968e767525a63fda4917b6176e89772358b8f479411e177510b0d744c26' 
  AND token = 'MS7EPEs6/0I8oBHIGLUif4OkymlkOHSCavgHbKKNicQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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