SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4be8c0e406d850dc9250d1a2ca5dc07bb4fa3d9e022d59eac3c2030992a5e7a1' 
  AND token = '0eu5V5MJa5hloO0KObtVwpetxwTjYd1eQJRr4bAe7hY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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