SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34d8b5f604d863e11819b1c0d148d0d72a42d2d5fc4ec096ede5ce9c95c8b980' 
  AND token = 'vqzfQjB67ldBBXJuAxMBRz0OYVmjhCtH6O31kPfq2HM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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