SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab04b032b07093e31a34c106a79af880119c45a380f4df568a69f33e9c2f3984' 
  AND token = '2uNyxL4KJistatwI/VVWN2+4KQJUHjmddLGxYjgKKI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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