SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93993a2df52eb5c136ade8a8ee4d83993e627a23715b6d01da455bc38f82842c' 
  AND token = '/Q1TPKoemy40QjWXC0mkPVH59mY3F0hxaZWgPwpZVAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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