SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6eb5ab316408c026332078da85d523cca03fa19cb779efcf915041a8d895bfd' 
  AND token = '9wav0bCR2Er2p8JJlbe+ohgJAFX2vW5kcHytRRSE948=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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