SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4a1a85386a313048045546639fd913a28ca5eb0e6b1ea1859cd0935b45aa397f' 
  AND token = 'cQ1lq7tnsupzrCNoD9xA0hW2tZMk6x3dVUQ3S/w3WI4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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