SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '711d74bb65b9cbb66d29028f08aa9065c9b4cbe856bc9357c849c7e601eb3455' 
  AND token = 'uhScRXiRz/gq2GOOZOhRrCeNzBwW0HT+/dDB4w/m0Jo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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