SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2689bef99914dc799d1437a013fd6e5ed878482406c15ebd342f09566cfcba50' 
  AND token = 'zzoCVx96ctVD+guCFSRf7O7HpyqJ9K8YVDF7PO/w52A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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