SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2260eb15bc3621032f179e3e9d4e21e7bd4b13078f058b11daf216dbb0b2bfe1' 
  AND token = 'lh8F4tLzxJWozFTYclotVb6S7UOJFSsdPALs2l9UPcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}