SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f282116ebaf41bc55bf2b34c1f38f7f49cad84847cf12969486a804d06a57064' 
  AND token = 'TEnWPGxNKnrbwCT43x+wn465rnxR29Gj+RS0GMAQVdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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