SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d020c00185a4b176b493566c55f5489a2ee288f40837cd8b0fa4411f0b3f58f' 
  AND token = '8KtZhnCuEjW20tI2QgRLuKPsM9g70eOmlzO7GUqzx4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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