SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03f186ad5009673f8da17e8c95b2d1b8c96e9e3c61f8def68802253c8a63600d' 
  AND token = 'KrtRb6+uy24uOm0smnsPQobxDtjNiwF5MxvEFy2cp/c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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