SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7d4203641e2ba8c37e49f0b3d5c64cac123c6abe68164d712ab09aa32f14893' 
  AND token = 'DSRpC+7pTFglVA66jZ7jLzkKCCIxqnhEihg1mY4eF1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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