SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fca2f8bdc882371d4f0b3bc28b740241037621ce9d9b01cd3c7cb3a8e5e992d5' 
  AND token = 'en/Ypmmh3nu/7qMmAsFLOS+eRK9D9tEIOruEoWi1Bco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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