SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc48617ef533c3b1871a5bd923ba62f3ac4766f67d42ee866960c1d18662d0f6' 
  AND token = 'ZUrvdgU5Q6Sp0/J8dG9ujVGKrtk8XZJb+agTQO+QQNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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