SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd1387360e855718f63ace230361e9a87e0140c2b8adf42732db73466902ff79' 
  AND token = 'tP/qazKw+xtDv/O5AWYDdXLFAqvcuNmeffy7GDTDj4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}