SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da4e5a7f02b075c41a9efc6abd62abdb774af70b9f35e235da8f1e17ec7dbadf' 
  AND token = '/HLsnX2Jcad2kMqrqhm1DJtrahdtQdpYbAdlZ0TT2PA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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