SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3952bcbf7c6b5e384bb89bd089628ec6fe8f81ffabe613ddea906a4484dda53e' 
  AND token = 'yVv9+fgw5TX+hKk4fPLlemQEZprzusUGorXMABeCawM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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