SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77b9b8213e00c4b5a0adcb319833c7a4b73fdbc0322fe17e3daf7a23c093c4e2' 
  AND token = 'CBlbV5Ly4Oi3wvPPdSwpA/G61mbEgb0g01enF0QeAm0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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