SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fc49fb8a86cd3251ef4df3f2ab164092dec8a28656602d222e91cd68b40de41' 
  AND token = 'TnbFIuY9CNWx/E6cOsgYcRDprdxm1LNRDiacRYy3LoM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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