SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a7aeb54becf071e9de3b678cf3e3210bdf1ac7ecde079749e3c386eb9917753' 
  AND token = 'ZYB41uxwcHYobGkFWjf2LHJgIFafJdt8aAohyyr7xdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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