SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58f7923b1c8ab96f4eb031e256334ac5ade664a529a2142c39e547890f3d4239' 
  AND token = 'HhUA/EI0cuRt+dDDPYBI5JrFdb4/WqWp/g+lGnbixmk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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