SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5072da06069f0c98dafa9e4158fdbaba2f8c464b516d622036dad5ce8ef1c409' 
  AND token = 'BvO2Cf+sQbIRJ7SaO2RGoBYiLRulojnfBFgq/YYOL0Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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