SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5bd5070edfbe2efe1e8d131b38bba72aef874c5856240ac355c6aee996549e7' 
  AND token = 'pekIvQ1Rw0uC1mDfeQBZUFH4ibkfotlFziVr7eiiesQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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