SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b105f21de65a12906f27ce7cb945fbf1a312fce58d60ee7354ba094551eff35d' 
  AND token = 'SvLingagajayMhceqJ3WotR7rrnOf5ZchfppNmxZCCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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