SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '71ab13b11f005bd9f4ed4af7822f1b18b3c05409bd673cfd3d6cf7a928cf3382' 
  AND token = '8lDrTn0vCIZpp4fG9jtLf6h7NIE7QzmWzt14xKDyBLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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