SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '156c6539e6b7503e1b11ed85fca133b91929c5cfc19921c71fad2553dac4a2ac' 
  AND token = '1Io7G5mgQyBOPr8v8JzvhdlHroNNYpRMst3gS4JVV9M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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