SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c453c464931bc1982eacad856b6f5d5231802f53ae425cb2185e25c5a5beb3f7' 
  AND token = 'SQe22gALPKo08tpOsy/OFpgMqvH7OgLTrcdF1olBvts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}