SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96381abb2993411d05264d954473179bcb2bf7b0e1e73f8ebf88d2d9ad25f608' 
  AND token = 'YZ0R+aUYMrH6Qe9KLLTrbroS2EzkgZQZFjGYSL9/z28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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