SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0afc1ae52bfb51d91bc96f22b2b421b5d27faff638f3697a22eb922282935ace' 
  AND token = 'nUAEZyuYFtT7TmIp1Br71Z7qAIdqjMfoZRRm+/Oe3xA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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