SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '527bdaf8ab459a61a472cc94cab7a8a448908e39d0038c80547ae220538f3d81' 
  AND token = 'tMX0758ATacM8n/1a3HuQndbz8+vExquZpG8Q4nJoLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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