SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4d4cf97a4bde9f9f968de96a32e256fa70ef1ebadaef5dd14a2b9ea3ce31d26' 
  AND token = 'UZTJ7AlD8XvPJ6PlKodpwhtapb2lPdbBvbsbLylTTCw=' 
  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"
    }
  }
}