SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c2c4848f84c9f0ee61f6cf55881bad99dc81cbb111d09bee89e5c1272524237' 
  AND token = 'tppInO5s+lKEOOfsvGLh4PMIvk1icmrkHE4Dt1NnpLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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