SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4701bec7d2afbe6bfaf9c77568b3ebce976a872341312b605280e748cad1d45' 
  AND token = 'Yw+dFAMlRv32aztkT/Hx5VXpjDPdLQ6ZYxzViR3cLbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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