SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a601a0a1ac66520b35d757beae460e973043503047bc4b46984d4d3dae81479' 
  AND token = 'XsZMx0g6GV7hPcYZBhyO+A/sP5/nKZYk1/Hsfu9da7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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