SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2099a670f8177be220a46894be40e6836b3d45308e8700518821f24435dc4879' 
  AND token = '/y/JFR17ug+BeF6WP1k7kJBV+F3Hy1vtZ2t3SvKXN1E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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