SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e57aedd52b606e7885f0264a0fef7ec7a8b56abe5483f87f3be74c16486e07da' 
  AND token = 'rqL4tdj493SpH0V+JZhFFz5MBNnZGDozeaTjCxPRoBk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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