SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf88cb855841db441d75c3ce23b52386d3c8dd382f970ae1c948c9fc3b7f8d41' 
  AND token = '/0tYm6N2XsJg47eZsZgspqHDEmbmV1XJJnwFfYIhDPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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