SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c1e93297009c957832436bc868b1d7f324576e1d2d59d34a796a31020491bae' 
  AND token = 'cWcdBomH4/q7DObbY6Jv9C1SEqvVq8e7X2w3qtj+M90=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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