SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11950c60fd64955d22cc00be9c7352db473d7832e9516ae9712cdf9abd44d32d' 
  AND token = 'XH4YsV1/r6mRKAGRd0LVZpPYTAjGwEe82AtW9yT+6Rg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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