SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ab1a4e4a2e171e4b7a05efc8198e528d5129f06675826cdc3a0955387ac807b' 
  AND token = 'X0xkGlOaORcXCYQ+uShQjPMX+vd4QtUjaWZF5BGNk6s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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