SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cae42394eca218ebcc79f929133b2498a0f8b035745a5613a962e4c320a4f65e' 
  AND token = 'e15+d87CKTCxJVFGsUilXiRRTWfMlNCt8P9VuYj03cU=' 
  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"
    }
  }
}