SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c1556522a760e57223c460208c587868fa9e7ebc384206bcc12d4398d6e4a26' 
  AND token = 'hb+YiNd840Hena8/FAvnPKsm5NPhxbpPs4Q+BKmg//s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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