SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ddacd8124d81160246da9187de78c988fa63fa52ab084cb02273109ee210974' 
  AND token = 'ugaZ3QCEvOHLg55vfbB4pFjN9dtSPUuDF4Pjfp294IQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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