SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20415cc09743bbdc9cb33c0b6fdaf5bfe28c56bd6e1fb55fc468e1fe1e07d81c' 
  AND token = 'kUJgDEtdZKFiUXBYnFYCNXP1AXeS0VTs5JWcGzB/Uec=' 
  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"
    }
  }
}