SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'abc269d95f5533604cd710258fad0b6a12d58892cb222c822426fb570fabac39' 
  AND token = '8qrbrTjPEWKcgPGqRqcNclc8LyYr9a4Kcgv6xKIHX44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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