SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99af4514cfe51602768ee389e9627a9f40bf1561eb172d1d66892d4d18a83522' 
  AND token = 'mi3FKbz2D8xfvztiRZUAhtq44vw55L7Grq2wdlFj/NY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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