SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03a62ac6fb6c9e0f39cf39ebbd363dd8990e2a4f8b16897a7a9342ef4455b97c' 
  AND token = 'Y7marCbDR4y/r3Zpa+r+0qfMFjoi8uU/HuYvVmUwJg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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