SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40970cfcceaa401734379d283d5867c6a64d662199f1aa4ff659d6209b37618a' 
  AND token = 'iKUH0ovAObTHq7HuKJrW32tFv60TVlbhj4ieXCC7sF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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