SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '103d7d206e53ceaae06444e5c3c2af879c2b1d7ebfc6b0a6671e5aeca98070c5' 
  AND token = '4c4D5SA2MDFLgYMOTGMRrApV0R0woEe5VcA1xA+KTSw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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