SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e89629aa08037ac187e35457b37cc47873d9f0ed0ef9b6df7b148e611f40dcd5' 
  AND token = 'sCHOyXtSIJukoq73xajNMqlRR6+OMnmMyHRd8VUDeb0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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