SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ddccab61dfde34b2cfa15caab7d4a099263a19a634c547f2354692cbb262e65' 
  AND token = 'N+NLD0Ty46V3ggjUFLqfEm4nEzPumhPMICIZW/AKSNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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