SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03026428a84d739ecef1ba4cc611c715040e038f543bef98bf0e27769e2e1acd' 
  AND token = 'KQDdjyj336qiSOcEhJ6ftxyTIgxP+uZa1hXabc3klVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}