SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40fc008ab364d9b83022be7f7a1d05c438965cedf15f0636ba5015182a7d29f1' 
  AND token = 'kn/YpZjB4OC6B9UYClsyRyyV0S9M2OBnIzUDEnQgXyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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