SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '162c1e3c194b13994d511d7b8ea8ff70b1930dce6e7828687e683a0a5533504e' 
  AND token = 'PvrqNjlKrnnWu37Bo36EHpRQMxwM3ob/Uhd+KgUJqw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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