SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a84a83b6eb3f36759e7d521084f12a25761e82b8e637194fbec3543625e57e6' 
  AND token = 'TSjXG48KjnBnvgjMIHqyNQWX8z+8EUTZrMF07OUfJqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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