SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4c73d2bfbf6ccd60233fce664ba83dea120989024a99cec6057a3b2d3262bafb' 
  AND token = 'aGU1ldVlVSjuxac03LcmdbI90GVRlxAspkkTmJ0JdO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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