SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed16cede2c1b15a39bab667a3f9243eea30049bbbac208ea5c46fba73a41141a' 
  AND token = '6gc8Rl9wCDRwkDuEcNIOiqXcZudNdq3588n5cXoxaEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}