SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e0dd3bb1ed1c88f4c2054aa71d978fc0a38ad19e37e04d9cdea26c942761ce7' 
  AND token = 'GqNg0odo09knWSbRIvGzpXaRyGrCxju0EVPcH/SyddE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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