SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d2a00f6d384e466dc30108bebd9823c082ccb13fd3d289406083dbb50a46a93' 
  AND token = 'SHMpFnlE7ZFZKy9qjxYen5kcgTjEnS2kgXrPh9F7Y8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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