SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '364b2495a10a2f3ac505d3abd4bd8f2690a35d0d18a68f8368fb12f1c8268771' 
  AND token = 'S582317X/hByHkjfVYe1bUwuD85bTruMekUzj+MHEao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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