SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bfadb281e2538f30d307289ae81d6933faf910584b53f1634b9ce45562ddca5' 
  AND token = 'p76gQCrd2ACBWzELxq0dVVPBgEbbAdbVvvG9smecaTI=' 
  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"
    }
  }
}