SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'cb8ba781b370f0744e99e0e31ef40de8a2fbcf7f6376f5966111d59a00a16090' 
  AND token = '6ICJYSGXU2kgzPnrzkMtA82R8j3+a1lkBz5ehvFnXiQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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