SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b358ffae99353efd1b30af09f7c0428e6bd879071db156da1f95775cd28887ab' 
  AND token = 'KxT/XsVgAlGQUFlyZehMWzogx9wRX+8EEX1G4W+kcLs=' 
  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"
    }
  }
}