SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cda414f1716cd2ed979b70e845833f079a328de81e4dc6510f0a18c1c6f9b9fc' 
  AND token = '7vm5Fe8kb0uCwpcNg0oxb5dFJ2a70ph2Z0JqT40b/bE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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