SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9722bb05e84a18bab601a4c1b3d3846fc198c5dd600be6fe7cb410d4ac36bd2c' 
  AND token = 'cp3sF7Wgt4c7dEW8NkUTUvIaxsTaNiPjycQNr8LAAxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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