SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '842aaf957ea75cd7d0110ffac1a1c09fe2c0f92761e5802ee9ec41163a0ab105' 
  AND token = 'Op6f0Iq2MGUdfXPQMVFYGpLta9mK/YQKfZ37d598I5w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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