SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0fc6c31c263dcdfa0a35a880df6febef0c0b652bc32c68e8d6152e3c12ba884' 
  AND token = 'zFUZPXmm2KhOnoMzmFS+a6lLgISej8O9XI3sWojDQIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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