SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02ed20339a52baa48039d59b396b5e3041926b904ef472bdb0026cd73030687c' 
  AND token = 't0zKBFwtIXMbsCtBk+K2+TLD7NAXKXF7Q/HBpX4/ZSE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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