SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0afd75a4ab95ad59bff88818bb0aa00996da0225c89a624ae34e0661818d3300' 
  AND token = 'OHwMxSy37epsu2Xv8FqjrEZu/0HfiScOrKG/4SmooR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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