SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d4d274465974b4dec7c4a59e47ce93874da3a1b4d5149d0a8b3e609c64c072a' 
  AND token = 'jHMHpRsO0+W4jsdsHvZpQTo/SsXhr2ICgfKrVVkItBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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