SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d4b7a182d020b3204a3346391f36952b32ca2a908876ce45a491a1a3c87972e' 
  AND token = 'J7+TfEjsCVwOz4BizRped3oGmGvEHyypCs4s7GgL5fY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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