SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '368f6e05827acd6104a81a3874588bad7eb817b5c105f55b7e9fcb98d9582e25' 
  AND token = 'lkATZ1xd50WI+GJcyY77WeG4OqJfDXCu8z/AGNeVBcc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00111

JSON explain

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