SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d62fffcd00e13d2268fd2af71ec40f092df5dcb847a870193331d66b997a4a3' 
  AND token = 'OjJIYTheUsqdRQ6KN8wpTZGhOV1X5Bte/ttSmMTSyHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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