SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc559f4adbdec5c69f083b074927aa2ef6a97b9abd018adad21ae86edeb89ebb' 
  AND token = 'AhrSLBuSJr8OHZE0cx2U6FT9TjQBa0y4LE6frhOoDZ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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