SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f183c83bd6bbe1938f30cdbd205e16a430fae51205905ddfde8a738e968f2d3' 
  AND token = 'UDlLICvGb8I0gFhRuvxTLSb62Jr9iYHzaN4RvfnjS1E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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