SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c62139c69307f33ac5bfb5571fbed5f05f92a3f3c4af33f135336a3b0d9bdd00' 
  AND token = 'FdI22x7iejNdTxO9DEiokmPLGetNa+ZxvKLcXGyfHKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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