SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d0e025af913a1119ae38c70d099a0ce9f09891b3b70a49fdcd745dcacdaa708' 
  AND token = 'hO7F7UwoY0NQEg4igNTpdrgtuMCYfVCF4xaQJIP79as=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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