SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a2f8fee6fd479282ffd0b74dd0590fb3db8514eac41c9a01270a4ad840fb786' 
  AND token = 'bwETm1lXpQAL9OvfcwOXlt3R9IZDGdeZcqTYkfyqX0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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