SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '157921e7d77dce61fb2fa4492a70631a59b5f4c70083c6525ddd16eeb463486c' 
  AND token = 'ClH2C5LLUFS8NRplkgIlMnGtAurINsF9HpCxGBcSqdM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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