SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd997f349c9b2ef25f20f464272a7a6b6614075bb953e2bfd65ae2410b0f0170c' 
  AND token = 'xtVHAaKHjzjQEcMyFstEezCmf5hxZC0MRuPn22neqZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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