SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0c4efb0a90fe1b373e8a2324c6405fe2609989db9e4498c267c1c953c752436' 
  AND token = 'ZKK+jQw4VGZDMxA2XfBGAGPWrG13+o/7AA6hx0RHQXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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