SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5119851cb05ab775d663ba2e9a6052303162d27c7b6ca94c1cc7d0c9469faa04' 
  AND token = 'wfYB26v8QV1dlTXVrJcIPZ67DhNbMgNjF6TzUZDP5+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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