SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '51a8668f6015b16e1a1f8ca419fa745b6dcc35737ec2ce66799002ec138e547c' 
  AND token = '+bv8VLQ/QfxflrsOw5IZanDkbCIIhsqM0jWHgJ5AfBg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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