SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ae86e1872575a5927ecd7e16d92c2c5204e933900f31fdd5c8f248728378472' 
  AND token = 'rDgQXZG9hRcNYz851gDcq/hRIyzT+sF1PrbBAjEyBH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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