SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '035e4cc249b8246cdfc9fc22f3803bfe8756d1606f3eb96cf2afc80763995b6a' 
  AND token = '2ztGFY7WLGpFXgz0zxVicKIZS9q1Z/3FGLeR/s8DKjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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