SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '26d8c17ca6df28239c7883f0089187481bffcd0d0cb61439d26654f9ab273b96' 
  AND token = 'iamH91g6vicIBH9n4TDiJo9aCi2v4NkqVsxXVAvfg5A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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