SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f61984ace1db0db70dabaac7ae34267d22ca2af0b3bdf7005d8e14560e997fc3' 
  AND token = 'CCoOlB39tENmBpJP40e0tgzYdtmn7HZp2QgVxKNnqzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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